Tunnel-lighting arrangement



April 14, 1970 P. J. BOLHUIS EI'AL 3,

TUNNEL-LIGHTING ARRANGEMENT med June 1, 1967 2 Sheets-Sheet 1 l4 Q INVENTORS PIETER J.BOLHUIS .IOZEF C-MOERKENS BY ,ZWQ z. AGE

A ril 14, 1970 P.J.BQLHU|S ETAL 3,506,821

TUNNEL-LIGHTING AERANGEMENT Filed June 1, 1967 2 Sheets-Sheet 2 INVENTOR3 United States Patent 3,506,821 TUNNEL-LIGHTING ARRANGEMENT Pieter Jan Bolhuis and Jozef Cornelis Moerkens,

Emmasingel, Eindhoven, Netherlands, assignors, by mesne assignments, to US. Philips Corporation, New York, N.Y., a corporation of Delaware Filed June 1, 1967, Ser. No. 642,814 Claims priority, application Netherlands, June 4, 1966, 6607797 Int. Cl. F21s 3/10 US. Cl. 2409 8 Claims ABSTRACT OF THE DISCLOSURE A tunnel lighting fixture has a closed housing of which one portion is translucent. A photosensitive element is mounted in the housing near the light source to receive light therefrom and is shielded from exterior light. A light filter having variable permeability is positioned between the light source and the photosensitive element, such that by varying the permeability, the amount of light striking the photosensitive element is varied, thereby affecting electric current control means and the light intensity.

The invention relates to a tunnel-lighting arrangement comprising a photosensitive element which is arranged in the tunnel, the lighting arrangement comprising at least one substantially closed lighting fitting, the

photosensitive element in the operating condition of the lighting fitting receiving light from a light source in the fitting and being connected to an electric device for supervising the tunnel-lighting; the invention also relates to lighting fittings for such tunnel-lighting arrangements.

A substantially closed lighting fitting is to be understood to mean herein a lighting fitting which in its operating condition comprises no or substantially no apertures which it communicates with the tunnel. Such a fitting is closed, for example, by means of a glass cover which forms part of the wall of the fitting.

Supervising the tunnel-lighting is to be understood to mean herein the checking and, if required, changing of the light level in the tunnel. The supervision may be automatic or non-automatic.

The electric device cooperating with the photosensiitve element comprises, for example, a photometer which is arranged in a supervision cabin of the tunnel. The electric device may alternatively be an automatically operating device which always adjusts the supply of energy to the light source of the lighting fitting at a desired value.

An advantage of the known arrangement is that the supervision of the tunnel-lighting is simple. In a known construction of the last' mentioned arrangements the photosensitive element is secured with its holder to the wall of the tunnel where it constitutes a projection. Such a discontinuity in the wall of the tunnel presents difiiculties, for example, if for cleaning the interior of the tunnel automatic cleaning lorries are used. When such a lorry passes, the photosensitive element may be damaged or the brushes of the cleaning lorry have to be retracted at the area of the photosensitive element. Although in the known arrangements the luminous decline as a result of the dirtiness of the tunnel fittings is taken into account, the cleaning of the interior of the tunnel is necessary after some time, because otherwise the lighting fittings become too dirty. In this connection it should be realized that a dirty lighting fitting reduces the efliciency of the lighting arrangement.

Another drawback of the known arrangements is that during normal operation dust and other dirt can accumulate on the photosensitive element. This adversely inice fluences a ready supervision of the tunnel lighting. In fact, the light level may be adjusted at too high a value which may lead to waste of electric energy. This effect is the more serious according as the frequency of cleaning the photosensitive element is lower.

It is the object of the invention to remove, at least to mitigate, the above drawbacks.

A tunnel-lighting arrangement according to the invention comprising a photosensitive element arranged in the tunnel, the lighting arrangement being provided with at least one substantially closed lighting fitting, the photosensitive element in the operating condition of the lighting fitting receiving light from a light source in the lighting fitting and being connected to an electric device for supervising the tunnel lighting, is characterized in that the photosensitive element is accommodated in the lighting fitting.

The automatic cleaning of the interior of the tunnel by means of the cleaning lorries normally used for this purpose now is a very simple job which is no longer hampered by discontinuities, namely, the photosensitive element with its holder. As a result of this, cleaning can also be effected more rapidly (which means smaller delay for normal tunnel trafiic) and the frequency of cleaning can more easily be increased which promotes the luminous efliciency of the light arrangement.

In a tunnel-lighting arrangement according to the invention, the dirtiness of the lighting fittings is no longer included in the measurements through the photosensitive element, but in view of the above described possibilities of more frequently cleaning the tunnel this is only of minor importance.

By providing the photosensitive element in the substantially closed lighting fitting, the problem of the dirtiness of this element and the above described unpleasant consequences thereof is reduced to substantially zero.

As a rule the tunnel-lighting arrangement will comprise more than one lighting fitting. It is not necessary that each lighting fitting comprises a photosensitive element. Of course the supervision of the tunnel lighting becomes better and more reliable according as more lighting fittings with photosensitive elements are used.

As already stated in the preamble the photosensitive element is connected to an electric device for supervising the tunnel lighting. This electric device is, for example, a meter which is arranged in the supervision cabin of the tunnel. The device may be adjusted, for example, so that the supervisor in charge can read from the positions of the hands of the meter whether the light sources approach their ends of their lives. He can then order in good time the replacements of the light sources by new ones.

If required, the arrangement may be constructed so that the supervisor can control the light intensity of the light sources in the tunnel from his cabin, for example, by varying the current intensity through the light sources. For example, in this manner he can readjust the tunnel lighting when the mains voltages decreases. This re-adjustment results from the information he gets from the said meter.

As a result of the fact that the photosensitive element is accommodated in the lighting fitting, so near a light source of the light arrangement, the lighting contribution to this element of other light sources, for example, motor-car headlights, will be small as a rule but in some cases not negligibly small which may be disadvantageous for the supervision.

Therefore the photosensitive element preferably is wholly or for the greater for part screened from light which originates from the outside the lighting fitting. An advantage hereof is, for example, that, for reading his meter, the supervisor need no longer wait until the tunnel is free from disturbing light sources, for example, motorcar headlights.

When the tunnel-lighting arrangement is provided with low pressure mercury vapour discharge lamps, the electric device connected to the photosensitive element preferably is an automatically operating control device of the tunnel lighting. In said lamps, which have a high luminous efficiency, the light output as a matter of fact rather depends upon the temperature which, in a non-automatically operating control device, would require very much attention of the supervisor on behalf of the light supervision. The electric control might take place, for example, with a known dimming device having reversely-connected thyristors. In long tunnels in which artificial light is desired also in the daytime, the said preferred device may be combined, if desired, with a device which also automatically involves the light level outside the tunnel in the supervision of the lighting level in the tunnel, but this combination is not necessary.

In a closed lighting fitting for a tunnel lighting arrange ment according to the invention, an adjustable light filter is preferably arranged between the light source of said fitting and the photosensitive element cooperating with the said light source.

Such an adjustable filter is of particular advantage since the distance between the light source and the photosensitive element is comparatively small. For explanation the following may be said. Of course, the exposure of the photosensitive element should give a measure of the light level in the tunnel. The exposure of the photosensitive element in the present case very strongly depends upon even small differences in the distance of this element to the light source. In order to hold said distance very constant, very stringent tolerance requirements regarding the arrangement of the photosensitive element with respect to the light source mould have to be imposed. This would be expensive. However, if an adjustable light filter is used this tolerance problem is avoided in a simple manner. A simple electrical solution of the said tolerance problem, for ex ample, through a variable resistor in series with the photosensitive element is less desirable since such a solution would produce a variation of the slope of the characteristic (that is to say of the quantity of light on the photosensiive element plotted against the total resistance of the circuit of this element or plotted against he voltage of said circuit).

The adjustable filter may consist, for example, of a device comprising movable glass strips with different permeabilities.

The light filter preferably is constructed as a rotatable disc which consists of parts having different permeabilities.

The permeability of the rotatable disc on the surface preferably varies continuously. The desired exposure of the photosensitive element can be very accurately adjusted by means of such a disc.

The light-pervious surface of the lighting fitting preferably form part of the surface of the wall of the tunnel. In this case the surface of the wall of the tunnel may be finished entirely smooth and the automatic cleaning of the interior of the tunnel is a particularly simple operation since as a matter of fact the wall of the tunnel comprises no projections or inlets.

In order that the invention may readily be carried into effect, it will now be described in greater detail, by way of example, with reference to the accomypanying drawings, in which:

FIGURE 1 shows a perspective view of a tunnel which is provided with a lighting arrangement according to the invention;

FIGURE 2 shows a part of a cross-sectional view of the tunnel taken on line AA of FIGURE 1 which plane extends at right angles to the axis of the tunnel and extends through a lighting fitting according to the invention;

FIGURE 3 shows on an enlarged scale a few details of FIGURE 2;

FIGURE 4 shows an elevation of an adjustable lightpervious filter with supporting member, viewed from the direction B shown in FIGURES 2 and 3;

FIGURE 5 is a block-schematic diagram of a tunnellighting arrangement having automatic supewision of the lighting.

In FIGURE 1, reference numeral 1 denotes the lanes of a tunnel. This tunnel has substantially smooth concrete walls which are covered with a layer of thin tiles. This holds both for the side walls and for the ceiling. The cross-section of the tunnel is approximately rectangular. Substantially closed lighting fittings 3, 4, 5 and so on, are provided in the left-hand top corner of the tunnel and similar fittings 3, 4' and so on are provided in the righthand top corner.

The lighting fitting 5 comprises a photosensitive element. The side of each lighting fitting facing the axis of the tunnel comprises a glass cover, see, for example, the cover glass of the fitting 5 denoted by 6 in FIGURE 2. The lighting fittings 3 and 4 (see FIGURE 1) are separated from each other by a concrete part 7 of the wall of the tunnel which is coated with thin tiles. The tiles of the part 7 of the wall and the sides of the cover glasses of the lighting fittings 3 and 4 facing the axis of the tunnel are located in the same plane. Another such concrete part of the wall covered with tiles is between the covers of the lighting fittings 4 and 5 and so on. Also the part 7 of the wall, in the right-hand top corner of the tunnel, is located in the same plane as that of the cover glass of the lighting fittings 3', 4 and so on.

FIGURE 2 is a cross-sectional view through a lefthand top corner of the tunnel shown in FIGURE 1, taken on the plane AA (see FIGURE 1). This plane extends through the lighting fitting 5 at the area of the device 8 (see FIGURE 2) which device comprises a photosensitive element which will be described in greater detail below. The device 8 is accommodated in the lighting fitting 5. 9 is a light source in the lighting fitting 5. It is a low-pressure mercury vapour discharge lamp of approximately 40 watts. A lamp holder of the lamp 9 is denoted by 10. The lighting fitting 5 has approximately a triangular cross-section. The side facing the interior of the tunnel is provided with a cover glass 6. The other sides 11 and 12 of the lighting fitting 5 are secured to the concrete of the tunnel by means of lag bolts 13, 13', 13", 13". 14 denotes a side and 15 the upper side of the interior of the tunnel. The cover glass 6 is secured in holders 16 and 17 of the lighting fitting 5. On its upper side the lighting fitting comprises an aperture 18 through which electric Wires 19 from the device 8 and possible wires for the supply of the light source 9 are conducted to a cable duct 20 in the upper wall 15 of the tunnel. This cable duct is closed by a cover 21, which is pivotable about the shaft 22 and engages an abutment member 23 while in use. The cover 21 is held in a horizontal position, for example, by means of a snap fastener (not shown).

The light source 9 transmits light to the interior of the tunnel (through the cover glass 6). A small part of the light transmitted by the light source 9 impinges upon the photosensitive element of the device 8.

FIGURE 3 shows in greater detail the device 8 which is arranged near the light source 9. The device 8 comprises a photosensitive resistor 24 which is secured to a holder consisting of a sheath-like part 25 and a supporting member 26. The axis of the sheath 25 approximately intersects the axis of the light source 9. The part 25 serves for screening light which originates from outside the lighting fitting 5. The strip-like part 26 is secured to the upper side 12 (see FIGURE 2) of the lighting fitting 5, for example, by welding.

A disc-shaped light filter 27 (see also FIGURE 4) is secured to the supporting member 26 (see FIGURE 3) by means of a screw 28. A spacing ring 29 is arranged between the supporting member 26 and the filter 27. The electric connections to the photosensitive resistor are denoted by 19. The connections of 19 to the photosensitive element 24 shown in FIGURE to be described below. A clip for securing the electric connections 19 to the supporting member 26 is denoted by 30.

The length of the light source 9 is well over one metre and the diameter of the disc 27 is approximately cms. This disc 27 has a permeability which depends upon an angle a (see FIGURE 4). a is the angle between a O-line on the filter (see FIGURE 4) and the vertical which extends through the screw 28 downwards (see the dot-anddash line in FIGURE 4). The larger at, the smaller the permeability of the part of the filter in front of the aperture of the sheath 25 (so also the smaller the exposure of the element 24). For adjusting a different angle a the screw 28 should be unscrewed somewhat and after rotating the disc 27 be screwed tight again.

In FIGURE 5 reference numeral 5 diagrammatically denotes the said lighting fitting. The light source 9, the photosensitive resistor and the disc 27 are accommodated in 5. FIGURE 5 further shows in block form a dimming device 31 and a control device 32. These latter devices are supplied from an alternating current main of approximately 220 volts, 50 c./s., namely through the terminals 33 and 34. Through the dimming device 31, the lamp 9 receives current (by means of the connections 35). Through the connections 19, the information regarding the operation of the lamp 9 is transmitted to the electric control device 32. The control device transmits the information received to the dimming device 31, through the wires 36, so that a new light level of the light source 9 and consequently of the tunnel can be adjusted, if required. Such a new adjustment takes place, for example, when the temperature falls as a result of which the low-pressure mercury vapour discharge lamp 19 will transmit a smaller amount of light. Through the element 24 the control device 32 will adjust the dimming device 31 to a somewhat higher current level so that the light level in the tunnel again increases.

As a result of the arrangement of the photosensitive element in a lighting fitting and as a result of the special profile of the inner surface of the tunnel (FIGURE 1) the tunnel shows no discontinuities so that cleaning by means of automatic cleaning lorries can be effected smoothly.

What is claimed is:

1. A light fixture having a light source for connection to a source of electric current and to control means for varying the light intensity of said light source, and comprising:

(a) a closed housing in which the light source is mounted, the housing including a translucent part through which light from the light source is emitted,

(b) a photo-sensitive element oriented in the housing for receiving light from said light source and operating said control means,

(c) a light filter having variable light permeability and disposed between the light source and the photosensitive element, and

(d) means for controlling the amount of light reaching the photosensitive element by varying the light permeability of the light filter, thereby affecting the control means and the resulting variation in light intensity of the source.

2. A system as defined in claim 1, further comprising means for screening the element from a substantial amount of the light originating outside the fixture.

3. A system as defined in claim 1, wherein the translucent portion of the housing constitutes part of the inner surface of the tunnel wall.

4. A system as defined in claim 3, wherein the housing when mounted in the tunnel has exposed outer surfaces which are substantially smooth providing no projections into the tunnel.

5. A system as defined in claim 1 wherein the filter is a rotatable disk.

6. A system as defined in claim 5, wherein the filter comprises movable glass strips each having different light permeabilities.

7. A system as defined in claim 1, wherein the light source is a low-pressure mercury vapor discharge lamp.

8. A system as defined in claim 1, wherein the housing is substantially sealed from dust and from light except for the transparent part.

References Cited UNITED STATES PATENTS 1,788,111 1/1931 Knowles 2409 X 1,905,251 4/1933 Styer.

1,981,206 11/1934 Strauss a- 24025 X 1,985,044 12/1934 Lyle.

2,199,394 5/1940 Dewan 240-9 2,526,828 10/ 1950 Phillips.

2,839,672 6/ 1958 Bobrick 2409 3,080,491 3/1963 Howell 2409 X 3,350,556 10/1967 Franck 24025 3,379,892 4/1968 Neagle 240-25 X OTHER REFERENCES Bulletin 34-101, Standard Flush Recessed Light Boxes for Built-in Lighting, published by Garey, Copy in 240- 78H, Ian. 18, 1935.

JOHN M. HORAN, Primary Examiner M. H. HAYES, Assistant Examiner U.S. Cl. X.R. 

